Edentate or partly edentate persons tend more and more to have their removable dentures replaced by firmly implanted teeth, either single or in the form of multiple tooth bridges, a fact that has led to the design of various shapes and kinds of implants to which a crown can be firmly and permanently attached.
The conventional and commonly used implant includes a fixture of Titanium provided with external and internal screw threads to be placed into the jaw bone.
The main drawback of these pin-shaped and threaded implants is the requirement of their being of sufficient length in order to support the tooth against forces caused by chewing and biting; this necessary length limits their insertion mainly into the frontal, incisor portion of the jaws, while the jaw bone along the lateral sides is in many cases too low for accommodating the long implants. In addition, the sinus cavities in the upper half of the skull are usually too close for providing sufficient bone depth for long implants of the above kind. Another obstacle is the mandibular nerve in the lower jaw, likewise limiting the depth or angulation to which the implant can penetrate. Still another disadvantage of the conventional implant is that the bore for insertion of the fixture has to be drilled more or less parallel to the outer contours of the jaw bone, whereby the direction of the axes of implant and tooth diverge to a large degree, and make rehabilitation a difficult task.
With the aim to overcoming the drawback of the long screw implant, various implants of shorter depth have been developed configured to enter the bone to a relatively low depth.
It is therefore the main object of the present invention to provide an implant designed for implanting artificial teeth in jaw portions regardless of low height, otherwise unsuitable for tooth restoration by means of conventional implants.
It is another object to provide an implant and an abutment configured to be attached to the implant at an angle not coaxial with the implant with the aim to fastening the crown in correct angular alignment.
Another object of the invention is to provide an implant that can withstand lateral forces in a more favorable manner than with the conventional implants.
Still another object is to remove from the jaw a minimum of bone material.